1. Faddeev, L.D.: The inverse problem in the quantum theory of scattering. II. Itogi Nauki i Tekhniki. Ser. Sovrem. Probl. Mat., 3. VINITI, Moscow, 93–180 (1974) (in Russian) [English translation: J. Soviet Math. 5:3, 334–396 (1976)]
2. Marchenko, V.A.: Sturm-Liouville Operators and Their Applications. Naukova Dumka, Kiev (1977) (in Russian) [English translation: Revised edition: AMS Chelsea Publishing, Providence, RI (2011)]
3. Yurko, V.A.: Introduction to the Inverse Spectral Problems Theory. Fizmatlit, Moscow (2007) (in Russian)
4. Dodd, R.K., Eilbeck, J.C., Gibbon, J.D., Morris, H.C.: Solitons and Nonlinear Wave Equations. Academic Press Inc., London (1984)
5. Zakharov, V.E., Manakov, S.V., Novikov, S.P., Pitaevskii, L.P.: Theory of Solitons. The Inverse Scattering Method. Nauka, Moscow (1980) (in Russian) [English translation: Consultants Bureau, New York (1984)]